Stringers for fasteners

ABSTRACT

A plastic fastener comprises two stringers. Each stringer includes a plurality of longitudinally spaced plastic engaging elements. The engaging elements of each stringer are interconnected via a plastic strip in which are embedded threads whereby each stringer is a unitary structure of molded plastic material. Each engaging element of each stringer extends transverse to the axis of the stringer and is provided with teeth or hooks at its both ends for meshing with engaging elements of the other stringer.

United States Patent Inventor Herbert Albert:

Rua Capitao Luiz Ramos 312, Sao Paulo, Brazil Appl. No. 845,455 FiledJuly 28, 1969 Patented Aug. 24, 1971 Priority Aug. 1, 1968 Brazil 201575STRINGERS FOR FASTENERS 9 Claims, 11 Drawing Figs.

US. Cl. 24/205.l2, 24/205.13 R Int. Cl AWN/08, A44b 19/10 Field ofSearch24/205.12, 205.13

Primary Examiner-Hemard A. Gelak Attorney-Camil P. Spiecens ABSTRACT: Aplastic fastener comprises two stringers. Each stringer includes aplurality of longitudinally spaced plastic engaging elements. Theengaging elements of each stringer are interconnected via a plasticstrip in which are embedded threads whereby each stringer is a unitarystructure of molded plastic material. Each engaging element of eachstringer extends transverse to the axis of the stringer and is providedwith teeth or hooks at its both ends for meshing with engaging elementsof the other stringer.

Patented Aug. 24, 1971 4 Sheets-Sheet 1 a. hi;

INVENTOR. Herbert Al beri's ATTORNEY I Patented Aug. 24, 1971 4Sheets-Sheet 2 Patented Aug. 24, 1971 4 Sheets-Sheet 8 I Patented Aug.24, 1971 3,600,756

4 Sheets-Sheet 4 I FIG] 12o FIG. 10

v 142 11 1 11 L. if. J

STRINGERS FOR FASTENERS This invention pertains to fasteners and moreparticularly to stringers for fasteners using molded plastics.

An object of the invention is to provide an improved fastener wherein itis not necessary to provide hems or flaps on the material to hide thefastener from view.

Another object of the invention is to provide an improved slide fastenerwherein stops are not required on the slide fastener per se for theslider.

A further object of the invention is to provide slide fasteners whereinthe stringers are sold in strips or rolls which are then cut to thedesired length so that it is not necessary to stock standard lengths.

It is yet another object of the invention to provide a slide fastenerwhich is easily attached to a piece of material by using a conventionalsewing machine without special feet.

It is a still further object of the invention to provide an improvedslide fastener which does not require the usual welted tapes foranchoring the teeth.

Briefly, the invention contemplates a stringer for a fastener. Thestringer comprises a plurality of plastic engaging elements. Theengaging elements extending in a longitudinally spaced sequence alongthe length of the stringer. Each engaging element has an upper end withat least one projection for meshing with similar projections of theengaging elements of the other stringer, and has a flat bottom end torest adjacent to a surface of its associated piece of material. Thestringer includes an array of threads extending at least longitudinallyand fixed to the bottom ends of the engaging elements. The threads aresurrounded by the same plastic material used for the engaging elementsso that the stringer is an integral unitary structure of molded plasticmaterial.

Other objects, the features and advantages of the invention will beapparent from the following detailed description of the invention whenread with the accompanying drawings wherein:

FIG. 1 is a perspective view of one embodiment of a slide fastener forconnecting two pieces of material using stringers in accordance with theinvention;

FIG. 2 is a top plan view of one of the stringers of the slide fastenerof FIG. 1;

FIG. 3 is a sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a side view of a portion of the slide fastener of FIG.

FIG. 5 is a front end view of the slider of the slide fastener of FIG.4;

FIG. 6 is a perspective view of a slide fastener using stringers inaccordance with another embodiment of the invention;

FIG. 7 is a side view of a portion of the pair of enmeshed stringers ofthe fastener of FIG. 6;

FIG. 8 is a bottom view of a portion of the pair of enmeshed stringersof the fastener of FIG. 6;

FIG. 9 is a bottom view of a portion of one of the stringers of FIG. 6;

FIG. 10 is a top view of a portion of one of the stringers of FIG. 6;and

FIG. 11 is a sectional view taken along the line l1ll of FIG. 10.

In FIG. 1, there is shown a slide fastener comprising: a first stringer20 sewn with thread 22 to a first piece of material 24; a secondstringer 26 sewn with thread 28 to asecond piece of material 30; and aslider 32. Since each stringer is the same only the stringer 20 will bedescribed in detail by making reference to FIGS. 1 to 4.

Stringer 20 comprises a plurality of engaging elements 34 extending inspaced relationship along its length. The engaging elements 34 are heldin interspaced positions by interconnecting means 36. A typical element34 has a base portion 38 with a flat bottom face 40 whose longitudinalends are provided with notches at 42 to accommodate interconnectingmeans 36. It should be noted that with respect to the engaging element34 its bottom is the end adjacent the material 24 and its top is the endremote therefrom as viewed particularly in FIG. 1. In fact, at least aportion of the bottom face 34 abuts flush with the material. Extendingfrom base 38 and integral therewith are outside upright portions 44 and46 and which span central portion 48. Cut in the faces of outsideupright portions 44 and 46 are recesses 50 and 52, respectively. In theface of each recess there is an indentation 54 and 56, respectively.Transversely overhanging and integral with each of the upright portions44 and 46 are projections or teeth 58 and 60, respectively. Passingthrough central portion 48 is a longitudinally widened hole 62 whose topedge is chamfered at 64 and cooperates with side chamfers 66 and 68 toprovide ridges whose function is hereinafter described.

Each of the interconnecting means 36 comprises either a plurality oflongitudinally extending textile threads or an open woven tape which isencompassable by plastic. During manufacture of the stringer 20 by aplastic molding operation the engaging elements 34 are molded fromplastic while the threads are simultaneously encased so that uponsetting an integral unitary structure is obtained. In other words, thethreads or tape are embedded in a plastic strip.

Stringer 20 is sewn onto one surface of the edge of the material 24 bymeans of a sewing machine, with a ramming or base guide, with the needlethereof passing through either the holes 62 of engaging elements 34 orthe space between the elements. The aforementioned ridges and chamfersdivert the sewing machine needle to these points.

Slider 32 in FIGS. 4 and 5 is provided with a wedge shaped centerpost 70extending between plates 72 and 74 having right angle bent edges such as76. These edges extend inward to form channels to guide the engagingelements 34. A pivotable lever pull 78 is connected to plate 74 and viaa connecting means and a spring (not shown) to pins 80 to move thelatter inward or outward. When the pins extend inward they will engageindentations 54 (See FIG. 4) to lock slider 32.

In order to enhance the flexibility of the stringers 20 and 26, theinterconnecting means 36 can be provided with perforations 37 (FIG. 2).

In FIG. 6, there is shown a slide fastener comprising: a first stringersewn with thread 122 to a first piece of material 124; a second stringer126 sewn with thread 128 to a second piece of material 130; and a slider132. Since each stringer is the same only one stringer will be describedin detail by making reference to FIGS. 7 to 11.

Stringer 120 comprises a plurality of engaging elements 134 extending inspaced relationship along thestringer length. The elements 134 are heldin interspaced positions by interconnecting means 136.

A typical engaging element 134 comprises a transversely extending bridgeor base portion 138 to the ends of which are connected upright portions140 and 142. It should be noted that the upright portions do notcompletely extend along the length of the bridge portion but are setback to provide a recess wall 143 best seen in FIG. 6. In addition, theupright portions are cut back at 141 to provide a track for the slider.The top of each upright portion is provided with a hook portion 144.(See FIG. 7). Hook portion 144 has an inclined top surface 156 and aflat engaging surface 158 which intersect to define the hook edge. Thehook portions 144 of an engaging element 134 are separated from eachother by a channel 146. The bottom of each upright portion is providedwith a flat surface 148 and 150 to rest flush against the material. (SeeFIG. 9). It should be noted that the upright portions 140 and 142 andbridge portion 138 surround the interconnecting means 136 whose bottomsurface 137 (FIG. 11) is level with the bottom surfaces of the uprightportions.

The interconnecting means 136 is a plurality of threads or an open woventape embedded in plastic to provide the backbone for the stringer 120and to define the positions and spacing of the engaging elements 134.

While the stringer 120 has been described as a plurality of distinctunits it is preferably a one piece integrated structure made of plasticand textile threads.

The stringer l20'can be made by an extrusion process, an injectionmolding process or and such similar processes wherein the fluid plasticused to form the engaging elements also saturates the spaces between thethreads or tape. In an injection molding process the threads or tape areplaced in the mold and then the fluid plastic introduced The mold is sodesigned that the wall of the cavity is flush with the portions of thethreads or tape which are between the engaging elements, i.e., theportion 152 of FIG. 9. Thus the stringer remains flexible after theplastic has set. In an extrusion process, the portions 152 aretemporarily made brittle and thereafter subject to a bending or similaroperation so thatthe plastic between the threads fractures so that thestringer is flexible when used.

A fastener using the stringers 120 and 122 has several advantages.Relative lateral movement of the stringers is impeded because a side ofthe hook portions 144 of one stringer abuts against the recesses 143 andthe interconnecting means 136 of the other stringer as can be seen inFIG. 7.

In addition the hook portions 144 are contoured with an inclinedtopsurface 156 and a flat engaging surface 158 so that a slider is notneeded, if desired. In such a case, the stringers are aligned one on topof the other and pressed together starting at a first end and proceedingto the second end. The hook portions 144 of the engaging elements 134will snap together because of the yieldability of the material as theseelements slide over the surfaces 156. The closure is maintained becauseof the abutting of the flat surfaces 158. Locking at the second or upperend of the fastener can be accomplished by providing a smaller spacingbetween several of the engaging elements near the upper end so that thehook portions 144 are subject to more pressure just like in the case ofconventional snap" fasteners.

The contour also permits separation of the stringers by a peelingoperation which starts at the second end.

When the stringers 120 and 126 are used with a slider 132 several pointsshould be noted. The end stops for the slider are easily provided bymaking sure that hook portions 144 of several of the engaging elementsat the ends of the slider are permanently set in abutting relationship.

If the fastener is to be used to close two pieces of material which arenonnally separated, such as a jacket front, the slider can be retainedon one of the stringers by making that stringer slightly longer than theother. End stops can be provided in the form described above or by atransverse seam or welt provided on the material at the ends of thestringer.

When the fastener is used to open or close two permanently joined piecesof material, the bottom stop for the fastener is easily obtained bysewing a transverse seam 118 (See FIG. 6) through the overlappingmaterial pieces 124 and 130 at the bottom end of the fastener. Thus theengaging elements at this end remain permanently enmeshed. Thisprocedure can be used for fasteners with sliders as well as thosewithout sliders.

The stringers are easily affixed to the material by a conventionalsewing machine which sews along the central portion of theinterconnecting means 136 and the bridge portion 138. When the bridgeportion is sufficiently thin to be pierced by the needle while sewing,no special guide holes are needed. If the bridge portion is thick thenchamfered guide holes such as shown in FIG. 2 can be used.

What I claim is: y

l. A fastener for connecting two pieces of material comprising a pair ofstringers, each of said stringers comprising a plurality of engagingelements longitudinally spaced from each other along the axis of thestringer, each of said engaging elements extending in a directiontransverse to the axis of said stringer, each of said engaging elementshaving a bottom surface with a portion of which is substantially flat torest adjacent a surface of its associated piece of material,.a pair ofupright portions extending upward from said bottom surface, a bridgeportion, each of said upright portions being at a different end or saidbridge portion and spaced from each other so that a channel is providedbetween said upright portions, means for connecting the bridge portionsof said engaging elements to the associated pieces of material so thatthe stringers arefixed to their associated pieces of material, at leaseone projection on the end of each of said uprightportions for meshingwith similar projections on the upright portions of the engagingelements of the other stringer and interconnecting means forinterconnecting the engaging elements along the bottom surfaces thereof,said engaging elements and said interconnecting means being made fromthe same material to form a unitary structure.

2. The fastener of claim 1 wherein said material is a plastic and withinsaid interconnecting means there are embedded threads that extend atleast longitudinally along the length of said stringer.

3. The fastener of claim 2 wherein said threads are arrayed in the formof an open woven tape.

4. The fastener of claim 2 wherein the plastic of the interconnectingmeans is fractured.

5. The fastener of claim 1 wherein said projections are hook elementsextending in the longitudinal direction of the stringer, thelateralspacing between the hook elements being such that said hook elements ofthe engaging elements of one stringer can straddle and abut portions ofthe sides of the engaging means of the other stringer.

6. The fastener of claim 5 wherein each hook element has a top surfacewhich is inclined with respect to the plane of the stringer and a flatundersurface which is substantially parallel to said plane, saidsurfaces intersecting at anacute angle.

7. The fastener of claim 1 wherein the spacing between the projectionsof adjacent engaging elements at at least one end of said stringers isless than the spacing between the other engaging elements of thestringers.

8. The fastener of claim 1 wherein there is at least one indentation inthe side of said upright portions for accepting the locking pin of aslider.

9. The fastener of claim 1 wherein the portion of said engaging elementbetween said upright portions is provided with a through passageway forreceiving a sewing machine needle.

1. A fastener for connecting two pieces of material comprising a pair ofstringers, each of said stringers comprising a plurality of engagingelements longitudinally spaced from each other along the axis of thestringer, each of said engaging elements extending in a directiontransverse to the axis of said stringer, each of said engaging elementshaving a bottom surface with a portion of which is substantially flat torest adjacent a surface of its associated piece of material, a pair ofupright portions extending upward from said bottom surface, a bridgeportion, each of said upright portions being at a different end or saidbridge portion and spaced from each other so that a channel is providedbetween said upright portions, means for connecting the bridge portionsof said engaging elements to the associated pieces of material so thatthe stringers are fixed to their associated pieces of material, at leaseone projection on the end of each of said upright portions for meshingwith similar projections on the upright portions of the engagingelements of the other stringer and interconnecting means forinterconnecting the engaging elements along the bottom surfaces thereof,said engaging elements and said interconnecting means being made fromthe same material to form a unitary structure.
 2. The fastener of claim1 wherein said material is a plastic and within said interconnectingmeans there are embedded threads that extend at least longitudinallyalong the length of said stringer.
 3. The fastener of claim 2 whereinsaid threads are arrayed in the form of an open woven tape.
 4. Thefastener of claim 2 wherein the plastic of the interconnecting means isfractured.
 5. The fastener of claim 1 wherein said projections are hookelements extending in the longitudinal direction of the stringer, thelateral spacing between the hook elements being such that said hookelements of the engaging elements of one stringer can straddle and abutportions of the sides of the engaging means of the other stringer. 6.The fastener of claim 5 wherein each hook element has a top surfacewhich is inclined with respect to the plane of the stringer and a flatundersurface which is substantially parallel to said plane, saidsurfaces intersecting at an acute angle.
 7. The fastener of claim 1wherein the spacing between the projections of adjacent engagingelements at at least one end of said stringers is less than the spacingbetween the other engaging elements of the stringers.
 8. The fastener ofclaim 1 wherein there is at least one indentation in the side of saidupright portions for accepting the locking pin of a slider.
 9. Thefastener of claim 1 wherein the portion of said engaging element betweensaid upright portions is provided with a through passageway forreceiving a sewing machine needle.